Display device

ABSTRACT

A display device such as liquid crystal display device which restrains the entrance of static electricity into a scanning signal driver circuit or a video signal driver circuit includes a pair of substrates, a signal line, a capacitance line and a counter voltage line formed on one substrate of the pair of substrate, a pixel including a thin film transistor connected to the signal line, a pixel electrode connected to the thin film transistor and a counter electrode connected to the counter voltage line, a driver circuit formed on the one substrate and connected to the signal line and an interconnection layer disposed between the pixel and the driver circuit. At least one of the capacitance line and the counter voltage line is connected to the interconnection layer between the driver circuit and the pixel.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image display device, and moreparticularly, to a liquid crystal display device in which a scanningsignal driver circuit and a video signal driver circuit are formed on aliquid-crystal-side surface of one of substrates disposed in oppositionto each other with a liquid crystal interposed therebetween.

2. Background Art

A liquid crystal display device includes a plurality of gate signallines disposed in juxtaposition and a plurality of drain signal linesjuxtaposed to intersect the plurality of gate signal lines on aliquid-crystal-side surface of one of substrates disposed in oppositionto each other with a liquid crystal interposed therebetween. Pixel areasare respectively formed by areas each surrounded by adjacent ones of thegate signal lines and adjacent ones of the drain signal lines, and eachof the pixel areas is provided with a switching element driven by ascanning signal from a corresponding one of the gate signal lines, and apixel electrode supplied with a video signal from a corresponding one ofthe drain signal lines via the switching element.

In addition, a scanning signal driver circuit and a video signal drivercircuit are formed on the liquid-crystal-side surface of the one of thesubstrates. The scanning signal driver circuit for progressivelysupplying scanning signals to the gate signals is formed on the side ofat least one end of each of the gate signal lines, while the videosignal driver circuit for supplying video signals in synchronism withthe timing of supplying the scanning signals is formed on the side of atleast one end of each of the drain signal lines.

SUMMARY OF THE INVENTION

However, it has been pointed out that in the liquid crystal displaydevice constructed in this manner, since the scanning signal drivercircuit or the video signal driver circuit is positioned in a peripheralportion of the substrate, problems easily occur owing to the entrance ofstatic electricity into the scanning signal driver circuit or the videosignal driver circuit.

In addition, it has been pointed out that in a liquid crystal displaydevice of the type in which a backlight is disposed in its rear portion,light from the backlight leaks to the side of an observer through aportion in which the scanning signal driver circuit or the video signaldriver circuit is formed.

Furthermore, it has been pointed out that since the scanning signaldriver circuit or the video signal driver circuit is formed on a surfaceof a substrate such as a glass substrate, no sufficient heat radiationeffect can be obtained and the scanning signal driver circuit or thevideo signal driver circuit is likely to malfunction.

The invention has been made in view of the above-described problems, andaims to provide a liquid crystal display device capable of restrainingstatic electricity from entering the scanning signal driver circuit orthe video signal driver circuit.

The invention also aims to provide a liquid crystal display devicecapable of restraining the leak of light through the portion in whichthe scanning signal driver circuit or the video signal driver circuit isformed.

The invention further aims to provide a liquid crystal display devicecapable of restraining the malfunction of the scanning signal drivercircuit or the video signal driver circuit.

According to a first embodiment of a display device of the presentinvention, there is provided for example, a pair of substrates, and asignal line, a capacitance line and a counter voltage line formed on onesubstrate of the pair of substrate, and a pixel comprising a thin filmtransistor connected to the signal line, a pixel electrode connected tothe thin film transistor and a counter electrode connected to thecounter voltage line, and a driver circuit formed on the one substrateand connected to the signal line, and a interconnection layer disposedbetween the pixel and the driver circuit.

At least one of the capacitance line and the counter voltage line isconnected to the interconnection layer between the driver circuit andthe pixel.

According to a modification of the first embodiment of the displaydevice of the present invention, for example, the signal line is a gatesignal line, and the driver circuit is a scanning signal driver circuit.According to a further modification of the first embodiment, forexample, the interconnection layer is disposed between the scanningsignal driver circuit and the pixel, and the scanning signal drivercircuit and a nearest edge of the one substrate to the scanning signaldriver circuit. And according to a further modification of the firstembodiment, at least one of the capacitance line and the counter voltageline is connected to the interconnection layer between the scanningsignal driver circuit and the nearest edge of the one substrate.According to another modification of the first embodiment, a width ofthe interconnection layer between the scanning signal driver circuit andthe pixel is smaller than a width of the interconnection layer betweenthe scanning signal driver circuit and the nearest edge of the onesubstrate.

According to another modification of the first embodiment of the presentinvention, for example, the capacitance line and the gate signal lineare made by same metal material and are disposed in a same layer. Andaccording to another modification of the first embodiment of the presentinvention, for example, the counter voltage line is formed to cover thescanning signal driver circuit.

According to another modification of the first embodiment of the displaydevice of the present invention, for example, the signal line is a drainsignal line, and the driver circuit is a video signal driver circuit.According to a further modification of the first embodiment, forexample, the interconnection layer is disposed between the video signaldriver circuit and the pixel, and the video signal driver circuit and anearest edge of the one substrate to the video signal driver circuit.And according to a further modification of the first embodiment, atleast one of the capacitance line and the counter voltage line isconnected to the interconnection layer between the video signal drivercircuit and the nearest edge of the one substrate. According to anothermodification of the first embodiment, a width of the interconnectionlayer between the video signal driver circuit and the pixel is smallerthan a width of the interconnection layer between the video signaldriver circuit and the nearest edge of the one substrate.

According to another modification of the first embodiment of the presentinvention, for example, the interconnection layer and the drain signalline are made by same metal material and are disposed in a same layer.According to a another modification of the first embodiment of thepresent invention, for example, the counter voltage line is formed tocover the video signal driver circuit.

According to a modification of the second embodiment of the displaydevice of the present invention, for example, a pair of substrates, anda signal line, a capacitance line and a counter voltage line formed onone substrate of the pair of substrate, and a pixel comprising a thinfilm transistor connected to the signal line, a pixel electrodeconnected to the thin film transistor and a counter electrode connectedto the counter voltage line, and a driver circuit formed on the onesubstrate and connected to the signal line, and a interconnection layerdisposed between the pixel and a nearest edge of the one substrate tothe driver circuit.

At least one of the capacitance line and the counter voltage line isconnected to the interconnection layer between the driver circuit andthe nearest edge of the one substrate.

According to a second embodiment of the display device of the presentinvention, for example, the signal line is a gate signal line, thedriver circuit is a scanning signal driver circuit, the interconnectionlayer is disposed between the scanning signal driver circuit and thenearest edge of the one substrate, and the scanning signal drivercircuit and the pixel, and a width of the interconnection layer betweenthe scanning signal driver circuit and the pixel is smaller than a widthof the interconnection layer between the scanning signal driver circuitand the nearest edge of the one substrate.

According to a modification of the second embodiment of the displaydevice of the present invention, for example, the signal line is a drainsignal line, and the driver circuit is a video signal driver circuit.According to another modification of the second embodiment, theinterconnection layer and the drain signal line are made by same metalmaterial and are disposed in a same layer.

According to a third embodiment of the display device of the presentinvention, for example, a pair of substrates, a plurality of pixelscomprising a plurality of pixel electrodes and a plurality of counterelectrodes formed on one substrate of the pair of substrates, aplurality of gate signal lines and a plurality of drain signal linesformed on the one substrate, a plurality of capacitance lines, and acounter voltage line connected to the plurality of counter electrodes, adriver circuit connecting at least one of the plurality of gate signallines and the plurality of drain signal lines, and a conductive layerrestraining static electricity from entering the driver circuit.

The conductive layer is formed adjacent to the driver circuit, and atleast one of the plurality of capacitance lines and the counter voltageline is connected to the conductive layer.

According to a modification of the second embodiment of the displaydevice of the present invention, for example, the conductive layer isformed on the driver circuit. According to another modification of thesecond embodiment of the display device of the present invention, forexample, the conductive layer is formed between the driver circuit andthe one substrate of the pair of substrates.

And according to other embodiments of the display device of the presentinvention, for example,

(1) A liquid crystal display device according to the invention includes,for example, at least pixels, gate signal lines and capacitance linesall of which are formed on a liquid-crystal-side surface of one ofsubstrates disposed in opposition to each other with a liquid crystalinterposed therebetween, the pixels constituting a liquid crystaldisplay part, the gate signal lines being respectively common to pixelgroups each made of pixels juxtaposed in one direction, the capacitancelines being respectively common to the pixel groups, and a scanningsignal driver circuit to which at least one end of each of the gatesignal lines is connected, and an interconnection layer formed tosurround the scanning signal driver circuit, and the interconnectionlayer being formed to be smaller in line width on the same side as theliquid crystal display part than on the opposite side to the liquidcrystal display part, and the capacitance lines being disposed tointersect the scanning signal driver circuit and be connected to theinterconnection layer on the opposite side to the liquid crystal displaypart.

(2) A liquid crystal display device according to the invention includes,for example, at least pixels, gate signal lines and capacitance linesall of which are formed on a liquid-crystal-side surface of one ofsubstrates disposed in opposition to each other with a liquid crystalinterposed therebetween, the pixels constituting a liquid crystaldisplay part, the gate signal lines being respectively common to pixelgroups each made of pixels juxtaposed in one direction, the capacitancelines being respectively common to the pixel groups, a scanning signaldriver circuit to which at least one end of each of the gate signallines is connected, and an interconnection layer formed to surround thescanning signal driver circuit, the interconnection layer being formedto be smaller in line width on the same side as the liquid crystaldisplay part than on the opposite side to the liquid crystal displaypart, the capacitance lines being made of an optically nontransmissivematerial, and being disposed to intersect a layer underlying thescanning signal driver circuit and be connected to the interconnectionlayer on the opposite side to the liquid crystal display part.

(3) A liquid crystal display device according to the invention includes,for example, on a liquid-crystal-side surface of one of substratesdisposed in opposition to each other with a liquid crystal interposedtherebetween, a plurality of gate signal lines disposed injuxtaposition, a plurality of drain signal lines juxtaposed to intersectthe gate signal lines, pixel areas each formed by an area surrounded byadjacent ones of the gate signal lines and adjacent ones of the drainsignal lines, a liquid crystal display part formed by an aggregation ofthe pixel areas, a switching element, a pixel electrode and a counterelectrode all of which are disposed in each of the pixel areas, theswitching element being driven by a scanning signal from a correspondingone of the gate signal lines, the pixel electrode being supplied with avideo signal from a corresponding one of the drain signal lines via theswitching element, the counter electrode being connected to a countervoltage signal line to generate an electric field between the counterelectrode and the pixel electrode, the counter electrode being formedintegrally with the counter voltage signal line and having a portionformed to cover the corresponding one of the drain signal lines and thecorresponding one of the gate signal lines with an insulating layerinterposed between the counter electrode and the corresponding ones, ascanning signal driver circuit to which at least one end of each of thegate signal lines is connected, and an interconnection layer formed tosurround the scanning signal driver circuit,

the interconnection layer being formed to be smaller in line width onthe same side as the liquid crystal display part than on the oppositeside to the liquid crystal display part, the counter voltage signal linebeing disposed to intersect a layer overlying the scanning signal drivercircuit and be connected to the interconnection layer on the oppositeside to the liquid crystal display part.

(4) In a liquid crystal display device according to the invention basedon the construction described in (3), the counter voltage signal line isformed to cover the whole of an area in which the scanning signal drivercircuit is formed.

(5) A liquid crystal display device according to the invention includes,for example, on a liquid-crystal-side surface of one of substratesdisposed in opposition to each other with a liquid crystal interposedtherebetween, a plurality of gate signal lines disposed injuxtaposition, a plurality of drain signal lines juxtaposed to intersectthe gate signal lines, pixel areas each formed by an area surrounded byadjacent ones of the gate signal lines and adjacent ones of the drainsignal lines, a liquid crystal display part formed by an aggregation ofthe pixel areas, a switching element, a pixel electrode and a counterelectrode all of which are disposed in each of the pixel areas, theswitching element being driven by a scanning signal from a correspondingone of the gate signal lines, the pixel electrode being supplied with avideo signal from a corresponding one of the drain signal lines via theswitching element, the counter electrode being connected to a countervoltage signal line to generate an electric field between the counterelectrode and the pixel electrode, the counter electrode being formedintegrally with the counter voltage signal line and having a portionformed to cover the corresponding one of the drain signal lines and thecorresponding one of the gate signal lines with an insulating layerinterposed between the counter electrode and the corresponding ones, avideo signal driver circuit to which at least one end of each of thedrain signal lines is connected, and an interconnection layer formedalong the video signal driver circuit on the opposite side to the liquidcrystal display part, the counter voltage signal line being disposed tointersect a layer overlying the video signal driver circuit and beconnected to the interconnection layer.

(6) A liquid crystal display device according to the invention includes,for example, on a liquid-crystal-side surface of one of substratesdisposed in opposition to each other with a liquid crystal interposedtherebetween, a plurality of gate signal lines disposed injuxtaposition, a plurality of drain signal lines juxtaposed to intersectthe gate signal lines, pixel areas each formed by an area surrounded byadjacent ones of the gate signal lines and adjacent ones of the drainsignal lines, a liquid crystal display part formed by an aggregation ofthe pixel areas, a switching element, a pixel electrode and a counterelectrode all of which are disposed in each of the pixel areas, theswitching element being driven by a scanning signal from a correspondingone of the gate signal lines, the pixel electrode being supplied with avideo signal from a corresponding one of the drain signal lines via theswitching element, the counter electrode being connected to a countervoltage signal line to generate an electric field between the counterelectrode and the pixel electrode, the counter electrode being formedintegrally with the counter voltage signal line and having a portionformed to cover the corresponding one of the drain signal lines and thecorresponding one of the gate signal lines with an insulating layerinterposed between the counter electrode and the corresponding ones, avideo signal driver circuit including a drain distribution circuit towhich at least one end of each of the drain signal lines is connected,and an interconnection layer formed to surround the drain distributioncircuit, the interconnection layer being formed to be smaller in linewidth on the same side as the liquid crystal display part than on theopposite side to the liquid crystal display part, the counter voltagesignal line being disposed to intersect a layer overlying the videosignal driver circuit and be connected to the interconnection layer.

(7) In a liquid crystal display device according to the invention basedon one of (5) and (6), the counter voltage signal line is formed tocover the whole of an area in which the video signal driver circuit isformed.

(8) A liquid crystal display device according to the invention includes,for example, on a liquid-crystal-side surface of one of substratesdisposed in opposition to each other with a liquid crystal interposedtherebetween, a plurality of gate signal lines disposed injuxtaposition, a plurality of drain signal lines juxtaposed to intersectthe gate signal lines, pixel areas each formed by an area surrounded byadjacent ones of the gate signal lines and adjacent ones of the drainsignal lines, a liquid crystal display part formed by an aggregation ofthe pixel areas, a switching element and a pixel electrode which aredisposed in each of the pixel areas, the switching element being drivenby a scanning signal from a corresponding one of the gate signal lines,the pixel electrode being supplied with a video signal from acorresponding one of the drain signal lines via the switching element, avideo signal driver circuit provided at first ends of the drain signallines, an equalizing circuit provided at second ends of the drain signallines, and an interconnection layer formed to surround the equalizingcircuit, the interconnection layer being formed to be smaller in linewidth on the same side as the liquid crystal display part than on theopposite side to the liquid crystal display part.

(9) A liquid crystal display device according to the invention based on(8) further includes a counter electrode which is connected to a countervoltage signal line to generate an electric field between the counterelectrode and the pixel electrode, the counter voltage signal line beingdisposed to intersect the equalizing circuit and be connected to theinterconnection layer on the side of the equalizing circuit opposite tothe liquid crystal display part.

(10) A liquid crystal display device according to the invention, forexample, includes on a liquid-crystal-side surface of one of substratesdisposed in opposition to each other with a liquid crystal interposedtherebetween, a plurality of gate signal lines disposed injuxtaposition, a plurality of drain signal lines juxtaposed to intersectthe gate signal lines, pixel areas each formed by an area surrounded byadjacent ones of the gate signal lines and adjacent ones of the drainsignal lines, a liquid crystal display part formed by an aggregation ofthe pixel areas, a switching element, a pixel electrode and a counterelectrode all of which are disposed in each of the pixel areas, theswitching element being driven by a scanning signal from a correspondingone of the gate signal lines, the pixel electrode being supplied with avideo signal from a corresponding one of the drain signal lines via theswitching element, the counter electrode being connected to a countervoltage signal line to generate an electric field between the counterelectrode and the pixel electrode, a video signal driver circuitprovided at first ends of the drain signal lines, an equalizing circuitprovided at second ends of the drain signal lines, and aninterconnection layer formed on the side of the equalizing circuitopposite to the liquid crystal display part, the counter voltage signalline being disposed to intersect the equalizing circuit and be connectedto the interconnection layer.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will become more readily appreciated and understood fromthe following detailed description of preferred embodiments of theinvention when taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is an explanatory view of the essential portions of Embodiment 1of the liquid crystal display device according to the invention.

FIG. 2 is a diagrammatic view showing the entire construction ofEmbodiment 1 of the liquid crystal display device according to theinvention.

FIG. 3 is an equivalent circuit diagram showing one embodiment of apixel of the liquid crystal display device according to the invention.

FIG. 4A is a diagrammatic view showing one embodiment of a pixel of theliquid crystal display device according to the invention and FIG. 4B isa sectional view of FIG. 4A taken along line b—b of FIG. 4A.

FIG. 5 is an explanatory view of the essential portions of amodification of Embodiment 1 of the liquid crystal display deviceaccording to the invention.

FIG. 6 is an explanatory view of the essential portions of anothermodification of Embodiment 1 of the liquid crystal display deviceaccording to the invention.

FIG. 7 is an explanatory view of the essential portions of anothermodification of Embodiment 1 of the liquid crystal display deviceaccording to the invention.

FIG. 8A is a diagrammatic view showing a scanning signal driver circuitand a peripheral portion thereof in Embodiment 1 of the liquid crystaldisplay device according to the invention and FIGS. 8B, 8C and 8D aresectional views of FIG. 8A taken along lines b—b, c—c and d—drespectively.

FIG. 9 is an explanatory view of the essential portions of Embodiment 2of the liquid crystal display device according to the invention.

FIG. 10 is an explanatory view of the essential portions of amodification of Embodiment 2 of the liquid crystal display deviceaccording to the invention.

FIG. 11 is an explanatory view of the essential portions of anothermodification of Embodiment 2 of the liquid crystal display deviceaccording to the invention.

FIG. 12 is an explanatory view of the essential portions of anothermodification of Embodiment 2 of the liquid crystal display deviceaccording to the invention.

FIG. 13A is a diagrammatic view showing the scanning signal drivercircuit and the peripheral portion thereof in Embodiment 2 of the liquidcrystal display device according to the invention and FIGS. 13B, 13C and13D are sectional views of FIG. 13A taken along lines b—b, c—c and d—drespectively.

FIG. 14A is a diagrammatic view showing the scanning signal drivercircuit and the peripheral portion thereof in Embodiment 3 of the liquidcrystal display device according to the invention and FIG. 14B is asectional view of FIG. 14A taken along line b—b of FIG. 14A.

FIG. 15 is an explanatory view of the essential portions of Embodiment 4of the liquid crystal display device according to the invention.

FIG. 16 is an explanatory view of the essential portions of amodification of Embodiment 4 of the liquid crystal display deviceaccording to the invention.

FIG. 17 is an explanatory view of the essential portions of anothermodification of Embodiment 4 of the liquid crystal display deviceaccording to the invention.

FIG. 18 is an explanatory view of the essential portions of anothermodification of Embodiment 4 of the liquid crystal display deviceaccording to the invention.

FIG. 19A is a diagrammatic view showing the scanning signal drivercircuit and the peripheral portion thereof in Embodiment 4 of the liquidcrystal display device according to the invention and FIGS. 19B, 19C and19D are sectional views of FIG. 19A taken along lines b—b, c—c and d—drespectively.

FIG. 20A is a diagrammatic view showing other examples of the scanningsignal driver circuit and the peripheral portion thereof in Embodiment 4of the liquid crystal display device according to the invention and FIG.20B is a sectional view of FIG. 20A taken along line b—b.

FIG. 21 is an explanatory view of the essential portions of Embodiment 5of the liquid crystal display device according to the invention.

FIG. 22 is an explanatory view of the essential portions of amodification of Embodiment 5 of the liquid crystal display deviceaccording to the invention.

FIG. 23 is an explanatory view of the essential portions of anothermodification of Embodiment 5 of the liquid crystal display deviceaccording to the invention.

FIG. 24 is an explanatory view of the essential portions of anothermodification of Embodiment 5 of the liquid crystal display deviceaccording to the invention.

FIG. 25A is a diagrammatic view showing the scanning signal drivercircuit and the peripheral portion thereof in Embodiment 5 of the liquidcrystal display device according to the invention and FIGS. 25B, 25C and25D are sectional views of FIG. 25A taken along lines b—b, c—c and d—drespectively.

FIG. 26 is an explanatory view of the essential portions of Embodiment 6of the liquid crystal display device according to the invention.

FIG. 27 is an explanatory view of the essential portions of amodification of Embodiment 6 of the liquid crystal display deviceaccording to the invention.

FIG. 28 is an explanatory view of the essential portions of anothermodification of Embodiment 6 of the liquid crystal display deviceaccording to the invention.

FIG. 29 is an explanatory view of the essential portions of anothermodification of Embodiment 6 of the liquid crystal display deviceaccording to the invention.

FIG. 30A is a view showing the construction of Embodiment 7 of theliquid crystal display device according to of the invention and FIG. 30Bis a sectional view of FIG. 30A taken along line b—b.

FIG. 31A is a view showing the construction of Embodiment 8 of theliquid crystal display device according to of the invention and FIG. 31Bis a sectional view of FIG. 31A taken along line b—b.

FIG. 32A is a view showing the construction of Embodiment 9 of theliquid crystal display device according to of the invention and FIG. 32Bis a sectional view of FIG. 32A taken along line b—b.

FIGS. 33A and 33B are views showing the construction of Embodiment 10 ofthe liquid crystal display device according to of the invention.

FIG. 34 is a view of the construction of a modification of Embodiment 10of the liquid crystal display device according to the invention.

FIG. 35 is a view of the construction of another modification ofEmbodiment 10 of the liquid crystal display device according to theinvention.

FIG. 36A is a diagrammatic view showing the scanning signal drivercircuit and the peripheral portion thereof in Embodiment 10 of theliquid crystal display device according to the invention and FIGS. 36B,36C and 36D are sectional views of FIG. 36A taken along lines b—b, c—cand d—d respectively.

FIG. 37 is an explanatory view of the essential portions of Embodiment11 of the liquid crystal display device according to the invention.

FIG. 38A is a circuit diagram of a video signal driver circuit and aperipheral portion of Embodiment 11 of the liquid crystal display deviceaccording to the invention and FIG. 38B is a diagrammatic view of thevideo signal driver circuit and the peripheral portion of Embodiment 11of the liquid crystal display device according to the invention and FIG.38C is a sectional view of FIG. 38B taken along line c—c.

FIG. 39 is a diagrammatic view showing other examples of the videosignal driver circuit and the peripheral portion thereof in Embodiment11 of the liquid crystal display device according to the invention.

FIG. 40 is a diagrammatic view showing other examples of the videosignal driver circuit and the peripheral portion thereof in Embodiment11 of the liquid crystal display device according to the invention.

FIG. 41A is a circuit diagram showing a video signal driver circuit anda peripheral portion of Embodiment 12 of the liquid crystal displaydevice according to the invention and FIG. 41B is a diagrammatic view ofFIG. 41A, and FIG. 41C is a sectional view taken along line c—c of FIG.41B.

FIG. 42 is a diagrammatic view showing examples of the video signaldriver circuit and the peripheral portion thereof in Embodiment 12 ofthe liquid crystal display device according to the invention.

FIG. 43A is a circuit diagram showing a video signal driver circuit anda peripheral portion of Embodiment 13 of the liquid crystal displaydevice according to the invention and FIG. 43B is a diagrammatic view ofFIG. 43A, and FIG. 41C is a sectional view taken along line c—c of FIG.41B.

FIG. 44 is a view showing the constructions of other examples of thevideo signal driver circuit and the peripheral portion thereof inEmbodiment 13 of the liquid crystal display device according to theinvention.

FIG. 45 is a view showing the constructions of other examples of thevideo signal driver circuit and the peripheral portion thereof inEmbodiment 13 of the liquid crystal display device according to theinvention.

FIG. 46 is an explanatory view of the essential portions of Embodiment14 of the liquid crystal display device according to the invention.

FIG. 47A is a circuit diagram showing a video signal driver circuit anda peripheral portion of Embodiment 14 of the liquid crystal displaydevice according to the invention and FIG. 47B is a diagrammatic view ofFIG. 47A, and FIG. 47C is a sectional view taken along line c—c of FIG.47B.

FIG. 48 is a view showing the constructions of other examples of thevideo signal driver circuit and the peripheral portion thereof inEmbodiment 14 of the liquid crystal display device according to theinvention.

FIG. 49 is a view showing the constructions of other examples of thevideo signal driver circuit and the peripheral portion thereof inEmbodiment 14 of the liquid crystal display device according to theinvention.

FIG. 50A is a circuit diagram showing a video signal driver circuit anda peripheral portion of Embodiment 15 of the liquid crystal displaydevice according to the invention and FIG. 50B is a diagrammatic view ofFIG. 50A, and FIG. 50C is a sectional view taken along line c—c of FIG.50B.

FIG. 51 is a view showing the constructions of other examples of thevideo signal driver circuit and the peripheral portion thereof inEmbodiment 15 of the liquid crystal display device according to theinvention.

FIG. 52 is a view showing the constructions of other examples of thevideo signal driver circuit and the peripheral portion thereof inEmbodiment 15 of the liquid crystal display device according to theinvention.

FIG. 53 is an explanatory view of the essential portions of Embodiment16 of the liquid crystal display device according to the invention.

FIG. 54 is an explanatory view of the essential portions of Embodiment17 of the liquid crystal display device according to the invention.

FIG. 55A is a circuit diagram showing a video signal driver circuit anda peripheral portion of Embodiment 17 of the liquid crystal displaydevice according to the invention and FIG. 55B is a diagrammatic view ofFIG. 55A, and FIG. 55C is a sectional view taken along line c—c of FIG.55B.

FIG. 56 is a view showing the constructions of other examples of theequalizing circuit and the peripheral portion thereof in Embodiment 17of the liquid crystal display device according to the invention.

FIG. 57 is a view showing the constructions of other examples of theequalizing circuit and the peripheral portion thereof in Embodiment 17of the liquid crystal display device according to the invention.

FIG. 58 is an explanatory view of the essential portions of Embodiment18 of the liquid crystal display device according to the invention.

FIG. 59A is a circuit diagram showing a video signal driver circuit anda peripheral portion of Embodiment 18 of the liquid crystal displaydevice according to the invention and FIG. 59B is a diagrammatic view ofFIG. 59A, and FIG. 59C is a sectional view taken along line c—c of FIG.59B.

FIG. 60 is a view showing the constructions of other examples of theequalizing circuit and the peripheral portion thereof in Embodiment 18of the liquid crystal display device according to the invention.

FIG. 61 is a view showing the constructions of other examples of theequalizing circuit and the peripheral portion thereof in Embodiment 18of the liquid crystal display device according to the invention.

FIG. 62A is a circuit diagram of the equalizing circuit of Embodiment 18of the liquid crystal display device according to the invention andFIGS. 62B and 62C are timing charts of the equalizing circuit of FIG.62A.

FIG. 63 is an explanatory view of Embodiment 20 of the liquid crystaldisplay device according to the invention.

FIG. 64 is an explanatory view of a modification of Embodiment 20 of theliquid crystal display device according to the invention.

DETAILED DESCRIPTION

Preferred embodiments of a liquid crystal display device according tothe invention will be described below with reference to the accompanyingdrawings.

EMBODIMENT 1

<<Entire Construction of Liquid Crystal Display Device>>

FIG. 2 is a diagrammatic view showing the entire construction ofEmbodiment 1 of the liquid crystal display device according to theinvention, and shows the construction of a liquid-crystal-side surfaceof one of transparent substrates opposed to each other with a liquidcrystal interposed therebetween.

As shown in FIG. 2, gate signal lines GL1, GL2, . . . (hereinafterreferred to simply also as gate signal line(s) GL) and drain signallines DL1, DL2, . . . (hereinafter referred to simply also as drainsignal line(s) DL) are formed in the central portion of a transparentsubstrate SUB1 except the periphery thereof. The gate signal lines GL1,GL2, . . . are disposed to be extended in the x direction and to bejuxtaposed in the y direction as viewed in FIG. 2, while the drainsignal lines DL1, DL2, . . . are disposed to be extended in the ydirection and to be juxtaposed in the x direction as viewed in FIG. 2.

Areas each of which is surrounded by adjacent ones of the gate signallines GL and adjacent ones of the drain signal lines DL constitute pixelarea, respectively, and an aggregation of this pixel area constitutes aliquid crystal display part AR. The detailed construction of each of thepixel areas will be described later.

The both ends of the gate signal lines GL are connected to scanningsignal driver circuits GSCL and GSCR, respectively, and scanning signalsare progressively supplied to the gate signal lines GL by the scanningsignal driver circuits GSCL and GSCR. Each of the scanning signal drivercircuits GSCL and GSCR is made of, for example, a multiplicity of MIS(metal insulator semiconductor) transistors having semiconductor layersusing polysilicon, and interconnection layers for interconnecting theseMIS transistors. Each of the scanning signal driver circuits GSCL andGSCR is formed on the surface of the transparent substrate SUB1.

One end (the top side of FIG. 2) of each of the drain signal lines DL isconnected to a video signal driver circuit. This video signal drivercircuit is made of a drain distribution circuit DDC formed on a sideclose to the drain signal lines DL, and a circuit IDC other than thedrain distribution circuit DDC. The drain distribution circuit DDC ismade of, for example, a multiplicity of MIS transistors havingsemiconductor layers using polysilicon, and interconnection layers forinterconnecting these MIS transistors. The drain distribution circuitDDC is formed on the surface of the transparent substrate SUB1. Thecircuit IDC is made of a semiconductor layer made of semiconductor chipsmounted on the transparent substrate SUB1. The other end (the bottomside of FIG. 2) of each of the drain signal lines DL is connected to anequalizing circuit EQC. This equalizing circuit EQC is made of, forexample, a multiplicity of MIS transistors having semiconductor layersusing polysilicon, and interconnection layers for interconnecting theseMIS transistors.

The scanning signal driver circuits GSCL and GSCR, the draindistribution circuit DDC and the circuit IDC are supplied with powersource voltages or signals from a power source and control circuit SCC.

FIG. 3 is a schematic view showing the equivalent circuit of the pixelarea. The pixel area is provided with a thin film transistor TFT to beelectrically connected an adjacent gate line and an adjacent drain lineand to be turned on by a scanning signal from the adjacent gate line GL,a pixel electrode PX to be supplied with a video signal from theadjacent drain line DL via this thin film transistor TFT, and a counterelectrode CT disposed in opposition to the pixel electrode PX andarranged to generate an electric field between the counter electrode CTand the pixel electrode PX. The counter electrode CT is supplied with asignal which serves as a reference for a video signal, via a countervoltage signal line CL. The optical transmissivity of the liquid crystalis controlled by a component parallel to the transparent substrate SUB1which component is contained in the electric field generated between thepixel electrode PX and the counter electrode CT.

A capacitance element Cstg is formed between the pixel electrode PX andthe counter voltage signal line CL so that a video signal supplied tothe pixel electrode PX is stored for a comparatively long time by thiscapacitance element Cstg.

The thin film transistor TFT has a semiconductor layer formed ofpolysilicon. The thin film transistor TFT has a constructionapproximately the same as the MIS transistor that is a constituent partof each of the scanning signal driver circuits GSCL and GSCR and thedrain distribution circuit DDC. Accordingly, the scanning signal drivercircuits GSCL and GSCR and the drain distribution circuit DDC aremanufactured in parallel with the manufacture of the construction of thepixel area.

<<Construction of Pixel>>

FIG. 4A is a plan view showing one embodiment of the construction of theabove-described pixel area. FIG. 4B is a cross-sectional view takenalong line b—b of FIG. 4A.

As shown in FIGS. 4A and 4B, a base insulating film ULS is formed on thesurface of the transparent substrate SUB1, and a semiconductor layer PSmade of polysilicon is formed on a part of the surface of the baseinsulating film ULS. This semiconductor layer PS constitutes asemiconductor layer of the thin film transistor TFT.

An insulating film GI is formed to cover the semiconductor layer PS onthe entire surface of the transparent substrate SUB1. This insulatingfilm GI functions as a gate insulating film of the thin film transistorTFT.

The gate signal lines GL1 and GL2 (hereinafter referred to also as thegate signal line(s) GL) which are disposed to be extended in the xdirection and to be juxtaposed in the y direction are formed on thesurface of the insulating film GI. These gate signal lines GL and thedrain signal lines DL which will be described later are disposed tosurround a rectangular area so that this rectangular area is constructedas a pixel area. In this case, each of the gate signal lines GL isformed to traverse the corresponding semiconductor layer PS, and aportion where each of the gate signal lines GL and the correspondingsemiconductor layer PS are superposed on each other functions as a gateelectrode of the thin film transistor TFT.

A capacitance signal line CST1 is formed approximately in the middlebetween each of the gate signal lines GL, i.e., approximately in themiddle of the pixel area in parallel with the gate signal lines GL. Thiscapacitance signal line CST1 is formed at the same time as the formationof the gate signal lines GL.

An interlayer insulating film IL1 is formed to cover each of the gatesignal lines GL and the capacitance signal lines CST1 on the entiresurface of the transparent substrate SUB1 on which the gate signal linesGL and the capacitance signal lines CST1 are formed in theabove-described manner.

The drain signal lines DL which are disposed to be extended in the ydirection and to be juxtaposed in the x direction are formed on thesurface of the interlayer insulating film IL1. Each of the drain signallines DL is connected to one end (drain region) of the correspondingsemiconductor layer PS through a through-hole CNT1 previously formed toextend through the interlayer insulating film IL1 and the insulatingfilm GI, and this connection portion also serves as a drain electrode ofthe thin film transistor TFT.

A pad layer PAD is formed at the same time as the formation of the drainsignal lines DL. The pad layer PAD is connected to the portion of thecapacitance signal line CST1 that is exposed in a through-hole CNT3formed in the interlayer insulating film IL1. This pad layer PADconstitutes an intermediate layer to be connected to the counterelectrode CT which will be described later.

The pixel electrode PX is formed at the same time as the formation ofthe drain signal lines DL. This pixel electrode PX is made of aplurality of (in FIG. 4A, two) strip-shaped electrodes which aredisposed to be extended in the y direction and to be juxtaposed in the xdirection, and the strip-shaped electrodes are formed in a pattern (anapproximately square θ-shaped pattern) in which the strip-shapedelectrodes are electrically connected to one another at a position abovethe capacitance signal line CST1 and at their end portions.

A part of the pixel electrode PX is connected to the other end (sourceregion) of the semiconductor layer PS through a through-hole CNT2previously formed to extend through the interlayer insulating film IL1and the insulating film GI, and this connection portion also serves as asource electrode of the thin film transistor TFT.

A protective film PAS made of an inorganic material and a protectivefilm FPAS made of an organic material are formed to be stacked in namedorder on the surface of the transparent substrate SUB1 on which thedrain signal lines DL, the pixel electrode PX and the like are formed.

The stacked structure of the protective films PAS and FPAS is formed inorder to avoid direct contact between the thin film transistors TFT andthe liquid crystal, and is also formed to be lowered in dielectricconstant.

The counter electrode CT is formed on the upper surface of theprotective film FPAS. The counter electrode CT is made of an opticallytransparent material such as ITO (Indium Tin Oxide), ITZO (Indium TinZinc Oxide), IZO (Indium Zinc Oxide), SnO₂ (Tin Oxide) and In₂O₃ (IndiumOxide). This counter electrode CT is made of a plurality of (in FIG. 4A,three) electrodes which are disposed to be extended in the y directionand to be juxtaposed in the x direction similarly to the pixel electrodePX, and the pixel electrode PX is positioned between each of the counterelectrodes in plan view. The counter electrode CT and the pixelelectrode PX are disposed at equal intervals in the order of counterelectrode, pixel electrode, counter electrode, pixel electrode, . . . ,and counter electrode from the drain signal line DL lying on one side tothe drain signal lines lying on the other side.

The counter electrodes CT which are respectively disposed on theopposite extreme sides of the pixel area are formed to be partlysuperposed on the respective drain signal lines DL, and are formed asthe counter electrodes CT shared by adjacent pixel areas, respectively.In other words, each of the counter electrodes CT is superposed on thecorresponding one of the drain signal lines DL so that their centralaxes approximately coincide with each other, and the width of each ofthe counter electrodes CT is formed to be larger than that of each ofthe drain signal lines DL. The portion of the counter electrode CT thatis located on the left side of each of the drain signal lines DLconstitutes one of the counter electrodes CT of the left-hand pixel areaas viewed in FIG. 4A, while the portion of the counter electrode CT thatis located on the right side of each of the drain signal lines DLconstitutes one of the counter electrodes CT of the right-hand pixelarea as viewed in FIG. 4A.

The construction in which the counter electrodes CT wider than the drainsignal lines DL are respectively formed over the drain signal lines DLin the above-described manner serves the advantage that lines ofelectric force from the drain signal lines DL are made to terminate atthe counter electrodes CT so that the lines of electric force can beprevented from terminating at the pixel electrode PX. If the lines ofelectric force from the drain signal lines DL terminate at the pixelelectrode PX, they will produce noise.

The counter electrodes CT each made of a plurality of electrodes areformed of the same material as and integrally with the counter voltagesignal lines CL which are formed to fully cover the respective gatesignal lines GL, so that a reference voltage is supplied to each of thecounter electrodes CT via the corresponding one of the counter voltagesignal lines CL.

As shown in FIG. 4A, a lead line CL1 for supplying a reference voltagesignal to the counter voltage signal lines CL and the counter electrodesCT is formed to extend between the capacitance signal line CST1 and oneof the gate signal lines GL which define the pixel area, in parallelwith these signal lines GL and CST1 in an area outside the liquidcrystal display area AR.

Optically transparent pixel electrodes PXT which overlap the respectivepixel electrodes PX are formed at the same time as the formation of thecounter electrodes CT and the counter voltage signal lines CL.

The capacitance element Cstg is formed between the pixel electrode PXand the capacitance signal line CST1, and this capacitance element Cstghas, for example, the function of storing a video signal supplied to thepixel electrode PX for a comparatively long time. As shown in FIG. 4A,the capacitance signal line CST1 has extended portions CPM formed tooverlap the respective pixel electrodes PX in order to increase thecapacitance of the capacitance element Cstg.

<<Constructions of Scanning Signal Driver Circuit and PeripheryThereof>>

FIG. 1 is a plan view showing the constructions of the scanning circuitsGSCL and the periphery thereof according to one embodiment.

As shown in FIG. 1, an interconnection layer COM which is connected tothe lead line CL1 of the counter voltage signal line CL and thecapacitance signal line CST1 is formed to surround the scanning signaldriver circuit GSCL.

This interconnection layer COM is provided with two terminals CP on aside where the scanning signal driver circuit GSCL is disposed, and isformed to run from one of the terminals CP through the portion betweenthe scanning signal driver circuit GSCL and the liquid crystal displaypart AR, extend to the side of the scanning signal driver circuit GSCLopposite to the liquid crystal display part AR, and reach the other ofthe terminals CP.

Accordingly, the scanning signal driver circuit GSCL can be protectedfrom external static electricity by the interconnection layer COM.

In this case, the line width of an interconnection layer COM2 disposedalong the scanning signal driver circuit GSCL on the same side as theliquid crystal display part AR is formed to be thinner than the linewidth of an interconnection layer COM1 disposed along the scanningsignal driver circuit GSCL on the opposite side to the liquid crystaldisplay area AR.

A multiplicity of gate signal lines GL extend from the scanning signaldriver circuit GSCL in the liquid crystal display part AR, and theinterconnection layer COM2 needs to be formed to traverse the gatesignal lines GL. By thinning the line width of the interconnection layerCOM2, it is possible to greatly decrease parasitic capacitance whichoccurs between the gate signal lines GL and the interconnection layerCOM2, thereby decreasing the delay of scanning signals on the gatesignal lines GL.

Accordingly, it is possible to prevent an increase in the electricalresistance of the interconnection layer COM itself by sufficientlythickening the line width of the interconnection layer COM1 on theopposite side to the liquid crystal display area AR by an amountcorresponding to the amount of thinning of the line width of theinterconnection layer COM2 on the same side as the liquid crystaldisplay part AR.

The counter voltage signal lines CL formed in the area of the liquidcrystal display part AR are connected via the lead lines CL1 to theinterconnection layer COM2 disposed on the same side as the liquidcrystal display part AR, while the capacitance signal lines CST1 passacross (intersect) the scanning signal driver circuit GSCL and areconnected to the interconnection layer COM1 disposed on the oppositeside to the liquid crystal display area AR.

In this case, since the capacitance signal lines CST1 are made of anoptically nontransparent material such as metal, the portions of thecapacitance signal lines CST1 serve a light blocking function, wherebythe leak of light from the rear to the front of a liquid crystal displaypanel can be decreased. In addition, the capacitance signal lines CST1have the role of heat radiation lines, and the heat of the scanningsignal driver circuit GSCL can be diffused and radiated on the entiresurface of the liquid crystal display panel through the heat radiationlines, whereby the scanning signal driver circuit GSCL can achieve itsnormal operation.

As shown in FIG. 5 by way of example, the interconnection layer COM mayalso be formed to surround completely the scanning signal driver circuitGSCL and to be supplied with a reference signal from one terminal CP.Furthermore, it goes without saying that, as shown in FIGS. 6 and 7, theinterconnection layer COM may be formed in such a manner that twoterminals CP are respectively provided at the mutually most distantlocations and a reference signal is supplied to each of the terminalsCP.

The interconnection layer COM which surrounds the scanning signal drivercircuit GSCL needs only to be formed along the scanning signal drivercircuit GSCL at least on the same side as and the opposite side to theliquid crystal display part AR, and the circuits formed on both sidesmay be electrically connected to each other.

FIG. 8A is a plan view showing a part of the scanning signal drivercircuit GSCL, and FIGS. 8B, 8C and 8D are cross-sectional views takenalong lines b—b, c—c and d—d of FIG. 8A, respectively.

As shown in FIGS. 8B, 8C and 8D, the interconnection layer COM is formedon the upper surface of the interlayer insulating film IL1, and isformed at the same time as the formation of, for example, the drainsignal lines DL.

As shown in FIG. 8B, the capacitance signal line CST1 is positioned tounderlie and intersect the scanning signal driver circuit GSCL with theinterlayer insulating film IL1 interposed therebetween. The connectionbetween the capacitance signal line CST1 and the interconnection layerCOM1 is provided through a through-hole formed in the interlayerinsulating film IL1.

In this case, since the capacitance signal line CST1 is formed of metal,the capacitance signal line CST1 has a light blocking function in aportion which intersects the scanning signal driver circuit GSCL,whereby the leak of light from the rear to the front of the liquidcrystal display panel can be decreased. In addition, the capacitancesignal line CST1 has the role of a heat radiation line, whereby thescanning signal driver circuit GSCL can achieve its normal operation.

As shown in FIG. 8D, the lead line CL1 of the counter voltage signalline CL is connected to an interconnection layer through a through-holewhich extends through the protective film FPAS and the protective filmPAS.

EMBODIMENT 2

FIG. 9 is a plan view showing Embodiment 2 of the liquid crystal displaydevice according to the invention, and is a view corresponding to FIG.1.

As compared with Embodiment 1 shown in FIG. 1, Embodiment 2 has adifferent construction in that the lead line CL1 of the counter voltagesignal line CL that is connected to the interconnection layer COM1formed along the scanning signal driver circuit GSCL on the oppositeside to the liquid crystal display part AR is formed to intersect thescanning signal driver circuit GSCL in a layer overlying the scanningsignal driver circuit GSCL.

According to this construction, the lead line CL1 can partly preventelectromagnetic waves from entering the scanning signal driver circuitGSCL from outside, thereby decreasing the malfunction of the scanningsignal driver circuit GSCL due to external noise.

In this case, the capacitance signal line CST1 is connected to theinterconnection layer COM2 formed along the scanning signal drivercircuit GSCL on the same side as the liquid crystal display part AR.

Incidentally, in this case as well, as shown in FIG. 10 by way ofexample, the interconnection layer COM may also be formed to surroundcompletely the scanning signal driver circuit GSCL and to be suppliedwith a reference signal from one terminal CP. Furthermore, it goeswithout saying that, as shown in FIGS. 11 and 12, the interconnectionlayer COM may be formed in such a manner that two terminals CP arerespectively provided at the mutually most distant locations and areference signal is supplied to each of the terminals CP.

FIG. 13A is a plan view showing a part of the scanning signal drivercircuit GSCL, and FIGS. 13B, 13C and 13D are cross-sectional views takenalong lines b—b, c—c and d—d of FIG. 13A, respectively.

As shown in FIG. 13B, the lead line CL1 of the counter voltage signalline CL is positioned to overlie and intersect the scanning signaldriver circuit GSCL, and is connected to the interconnection layer COM1through a through-hole formed to extend through the protective film FPASand the protective film PAS.

As shown in FIG. 13D, the capacitance signal line CST1 is connected tothe interconnection layer COM2 through a through-hole which extendsthrough the interlayer insulating film IL1 overlying the capacitancesignal line CST1.

EMBODIMENT 3

FIG. 14A is a plan view showing a part of the scanning signal drivercircuit GSCL, and is a view corresponding to FIG. 13A. FIG. 14B is across-sectional view taken along line b—b of FIG. 14A.

As compared with Embodiment 2 shown in FIG. 13A, Embodiment 3 has adifferent construction in that the lead line CL1 of the counter voltagesignal line CL is formed to cover the entire area of the scanning signaldriver circuit GSCL.

According to this construction, the lead line CL1 can approximatelycompletely prevent electromagnetic waves from entering the scanningsignal driver circuit GSCL from outside, thereby preventing themalfunction of the scanning signal driver circuit GSCL due to externalnoise.

EMBODIMENT 4

FIG. 15 is a plan view showing Embodiment 4 of the liquid crystaldisplay device according to the invention, and is a view correspondingto FIG. 9.

As compared with Embodiment 3 shown in FIG. 9, Embodiment 4 has adifferent construction in that the lead line CL1 of the counter voltagesignal line CL that is formed to intersect the scanning signal drivercircuit GSCL is connected not only to the interconnection layer COM1disposed on the opposite side to the liquid crystal display part AR butalso to the interconnection layer COM2 disposed on the same side as theliquid crystal display part AR.

This construction serves the advantage that even if disconnection occursin the interconnection layer COM1 disposed on the opposite side to theliquid crystal display part AR, a reference signal can be reliablysupplied to the counter voltage signal line CL.

Incidentally, in this case as well, as shown in FIG. 16 by way ofexample, the interconnection layer COM may also be formed to surroundcompletely the scanning signal driver circuit GSCL and to be suppliedwith a reference signal from one terminal CP. Furthermore, it goeswithout saying that, as shown in FIGS. 17 and 18, the interconnectionlayer COM may be formed in such a manner that two terminals CP arerespectively provided at the mutually most distant locations and areference signal is supplied to each of the terminals CP.

FIG. 19A is a plan view showing a part of the scanning signal drivercircuit GSCL, and FIGS. 19B, 19C and 19D are cross-sectional views takenalong lines b—b, c—c and d—d of FIG. 19A, respectively.

As shown in FIG. 19B, the lead line CL1 of the counter voltage signalline CL is connected to the interconnection layer COM1 disposed on theopposite side to the liquid crystal display part AR and to theinterconnection layer COM2 disposed on the same side as the liquidcrystal display part AR, respectively, through through-holes formed inthe protective film FPAS and the protective film PAS.

In this case, as shown in FIGS. 20A and 20B, the lead line CL1 of thecounter voltage signal line CL may be formed to cover the entire area ofthe scanning signal driver circuit GSCL, and may be connected atrequired locations to the interconnection layer COM1 disposed on theopposite side to the liquid crystal display part AR and to theinterconnection layer COM2 disposed on the same side as the liquidcrystal display part AR.

EMBODIMENT 5

FIG. 21 is a plan view showing Embodiment 5 of the liquid crystaldisplay device according to the invention, and is a view correspondingto FIG. 15.

As compared with Embodiment 4 shown in FIG. 15, Embodiment 5 has adifferent construction in that both the capacitance signal line CST1 andthe lead line CL1 of the counter voltage signal line CL are connected toonly the interconnection layer COM2 disposed on the same side as theliquid crystal display part AR.

Incidentally, in this case as well, as shown in FIG. 22 by way ofexample, the interconnection layer COM may also be formed to surroundcompletely the scanning signal driver circuit GSCL and to be suppliedwith a reference signal from one terminal CP. Furthermore, it goeswithout saying that, as shown in FIGS. 23 and 24, the interconnectionlayer COM may be formed in such a manner that two terminals CP arerespectively provided at the mutually most distant locations and areference signal is supplied to each of the terminals CP.

FIG. 25A is a plan view showing a part of the scanning signal drivercircuit GSCL, and FIGS. 25B, 25C and 25D are cross-sectional views takenalong lines b—b, c—c and d—d of FIG. 25A, respectively.

As shown in FIG. 25B, the lead line CL1 of the counter voltage signalline CL is connected to the interconnection layer COM2 disposed on thesame side as the liquid crystal display part AR, through a through-holeformed to extend through the protective film FPAS and the protectivefilm PAS.

As shown in FIG. 25D, the capacitance signal line CST1 is connected tothe interconnection layer COM2 disposed on the same side as the liquidcrystal display part AR, through a through-hole formed in the interlayerinsulating film IL1 overlying the capacitance signal line CST1.

EMBODIMENT 6

FIG. 26 is a plan view showing Embodiment 6 of the liquid crystaldisplay device according to the invention, and is a view correspondingto FIG. 21.

As compared with Embodiment 5 shown in FIG. 21, Embodiment 6 has adifferent construction in that both the capacitance signal line CST1 andthe lead line CL1 of the counter voltage signal line CL are connected tothe interconnection layer COM1 and the interconnection layer COM2disposed on the same side as and on the opposite side to the liquidcrystal display part AR.

Incidentally, in this case as well, as shown in FIG. 27 by way ofexample, the interconnection layer COM may also be formed to surroundcompletely the scanning signal driver circuit GSCL and to be suppliedwith a reference signal from one terminal CP. Furthermore, it goeswithout saying that, as shown in FIGS. 28 and 29, the interconnectionlayer COM may be formed in such a manner that two terminals CP arerespectively provided at the mutually most distant locations and areference signal is supplied to each of the terminals CP.

EMBODIMENT 7

FIG. 30A is a plan view showing a pixel of the liquid crystal displaydevice according to Embodiment 7 of the invention, and is a viewcorresponding to FIG. 4A. FIG. 30B is a cross-sectional view taken alongline b—b of FIG. 30A.

As compared with Embodiment 1 shown in FIG. 4A, Embodiment 7 has adifferent construction in that the lead line CL1 of the counter voltagesignal line CL is formed in the entire area between the liquid crystaldisplay part AR and the scanning signal driver circuit GSCL. In otherwords, the lead line CL1 is formed in not a linear pattern but a planepattern.

As described above, the counter electrode CT of each of the pixel areasis formed to cover the drain signal line DL and the gate signal line GL,and an extended portion of the counter electrode CT forms the countervoltage signal line CL.

In this formation, the lead line CL1 can be formed to extend and coverthe entire area of the scanning signal driver circuit GSCL.

EMBODIMENT 8

FIG. 31A is a plan view showing a pixel of the liquid crystal displaydevice according to Embodiment 8 of the invention, and is a viewcorresponding to FIG. 4A. FIG. 31B is a cross-sectional view taken alongline b—b of FIG. 31A.

As compared with Embodiment 1 shown in FIG. 4A, Embodiment 8 has adifferent construction in that no through-holes (CNT3 and CNT4) forproviding electrical connection between the capacitance signal line CST1and the counter electrode CT (the counter voltage signal line CL) areprovided in any of the pixel areas. This is because since thecapacitance signal line CST1 and the counter electrode CT (the countervoltage signal line CL) are connected to the interconnection layer COM,such through-holes (CNT3 and CNT4) are not needed.

This construction can improve the aperture ratio of each pixel.

EMBODIMENT 9

FIG. 32A is a plan view showing a pixel of the liquid crystal displaydevice according to Embodiment 9 of the invention, and is a viewcorresponding to FIG. 31A. FIG. 32B is a cross-sectional view takenalong line b—b of FIG. 32A.

As compared with Embodiment 8 shown in FIG. 31A, Embodiment 9 has adifferent construction in that the lead line CL1 of the counter voltagesignal line CL is formed in the entire area between the liquid crystaldisplay part AR and the scanning signal driver circuit GSCL. In otherwords, the lead line CL1 is formed in not a linear pattern but a planepattern.

EMBODIMENT 10

FIG. 33A is a plan view showing Embodiment 10 of the liquid crystaldisplay device according to the invention, and is a view correspondingto FIG. 1A. FIG. 33B is a cross-sectional view taken along line b—b ofFIG. 33A.

As shown in FIG. 33A, the scanning signal driver circuit GSCR providedon the side of the other end of the liquid crystal display part AR isalso given a function similar to that of the scanning signal drivercircuit GSCL shown in FIG. 1.

Accordingly, a construction similar to that shown in FIG. 1 is obtainedby reversing the construction of FIG. 1 between the right side and leftside about the y axis that passes through the center of the scanningsignal driver circuit GSCR as viewed in FIG. 1.

It goes without saying that the construction of any of theabove-described embodiments may be adopted as a modification of theperipheral construction of the scanning signal driver circuit GSCRprovided on the side of the other end of the gate signal lines GL.

Incidentally, in this case as well, as shown in FIG. 33B by way ofexample, the interconnection layer COM may also be formed to surroundcompletely the scanning signal driver circuit GSCL and to be suppliedwith a reference signal from one terminal CP. Furthermore, it goeswithout saying that, as shown in FIGS. 34 and 35, the interconnectionlayer COM may be formed in such a manner that two terminals CP arerespectively provided at the mutually most distant locations and areference signal is supplied to each of the terminals CP.

FIG. 36A is a plan view showing a part of the scanning signal drivercircuit GSCL, and FIGS. 36B, 36C and 36D are cross-sectional views takenalong lines b—b, c—c and d—d of FIG. 36A, respectively.

EMBODIMENT 11

FIG. 37 is a plan view showing Embodiment 11 of the liquid crystaldisplay device according to the invention, and shows the constructionsof the video signal driver circuit and the periphery thereof.

This video signal driver circuit is provided with the drain distributioncircuit DDC on the same side as the liquid crystal display part AR. Thedrain distribution circuit DDC has semiconductor devices made ofpolysilicon and interconnection layers for interconnecting thesemiconductor devices, on a surface of the transparent substrate SUB1.

In addition, in the video signal driver circuit, the circuits except thedrain distribution circuit DDC are made of a plurality of semiconductorchips TCP mounted on, for example, the transparent substrate SUB1.

A series of video signals, for example, three video signals, areinputted from one of the terminals of each of the semiconductor chipsTCP to the drain distribution circuit DDC via one interconnection layer,and are respectively outputted in parallel to the respective drainsignal lines DL, such as drain signal lines DL1, DL2, DL3, . . . by thedrain distribution circuit DDC.

According to this construction, it is possible to reduce the number ofthe semiconductor chips TCP with respect to the number of the drainsignal lines DL.

The interconnection layer COM is formed to surround the draindistribution circuit DDC, and is connected to the lead line CL1 of thecounter voltage signal line CL in the liquid crystal display part AR.

In this case, the line width of the interconnection layer COM2 disposedalong the drain distribution circuit DDC on the opposite side to theliquid crystal display part AR is formed to be thinner than the linewidth of the interconnection layer COM1 disposed along the draindistribution circuit DDC on the opposite side to the liquid crystaldisplay part AR.

A multiplicity of drain signal lines DL run from the drain distributioncircuit DDC in the liquid crystal display part AR, and theinterconnection layer COM2 which needs to be formed to intersect thedrain signal lines DL is thinned in line width so that it is possible togreatly decrease parasitic capacitance which occurs between the drainsignal lines DL and the interconnection layer COM2, thereby decreasingthe delay of scanning signals on the drain signal lines DL.

FIG. 38A is a circuit diagram showing one embodiment of the draindistribution circuit DDC, and corresponds to the portion of the area Bshown in FIG. 37.

Three video signals which are continuously outputted from one of thesemiconductor chip TCP are respectively outputted in parallel to thecorresponding drain signal lines DL1, DL2 and DL3 via three switchingelements Tr1, Tr2 and Tr3 each of which is to be turned on insynchronism with the timing of outputting of a respective one of thethree video signals.

FIG. 38B is a plan view showing one embodiment of an interconnectionpattern of the drain distribution circuit DDC formed on the surface ofthe transparent substrate SUB1, and shows a design geometricallycorresponding to the circuit diagram shown in FIG. 38A.

FIG. 38C is a cross-sectional view taken along line c—c of FIG. 38B. Thelead line CL1 of the counter voltage signal line CL formed in each ofthe pixel areas of the liquid crystal display part AR is formed toextend onto an area in which the drain distribution circuit DDC isformed, and is electrically connected to the interconnection layer COM2disposed along the drain distribution circuit DDC on the same side asthe liquid crystal display part AR and to the interconnection layer COM1disposed along the drain distribution circuit DDC on the opposite sideto the liquid crystal display part AR.

The interconnection layer COM is formed in the same layer as the gatesignal line GL, and the upper surfaces of the interconnection layer COMand the gate signal line GL are covered with the interlayer insulatingfilm IL1, the protective film PAS and the protective film FPAS in namedorder. The lead line CL1 of the counter voltage signal line CL is formedon the upper surface of the protective film FPAS, and the electricalconnection between the lead line CL1 and the interconnection layer COMis provided through through-holes formed to extend through theprotective film FPAS, the protective film PAS and the interlayerinsulating film IL1. Such electrical connection is provided viaintermediate layers which are formed between the lead line CL1 of thecounter voltage signal line CL and the interconnection layer COM at thesame time as the formation of the drain signal lines DL. Theintermediate layers are intended to decrease contact resistance.

FIGS. 39 and 40 are plan views showing another embodiment of the liquidcrystal display device according to the invention, and are views eachcorresponding to FIG. 38B.

The number of counter voltage signal lines CL disposed to intersect thedrain distribution circuit DDC is four for each predetermined lengththereof, for example, in the case of the construction shown in FIG. 38Band two, for example, in the case of the construction shown in FIG. 39.In the case of the construction shown in FIG. 40, the counter voltagesignal lines CL disposed to intersect the drain distribution circuit DDCare formed to cover the whole of the area in which the draindistribution circuit DDC is formed. In the case of the constructionshown in FIG. 40, there is an advantage which decreases the electricalresistances of the counter voltage signal lines CL and theinterconnection layer COM itself.

EMBODIMENT 12

FIGS. 41A, 41B and 41C are views showing the construction of anotherembodiment of the liquid crystal display device according to theinvention, and are views corresponding to FIGS. 38A, 38B and 38C,respectively.

As compared with Embodiment 11 shown in FIGS. 38A, 38B and 38C,Embodiment 12 has a different construction in that the interconnectionlayer COM2 disposed along the drain distribution circuit DDC on the sameside as the liquid crystal display part AR and the interconnection layerCOM1 disposed along the drain distribution circuit DDC on the oppositeside to the liquid crystal display part AR are formed in the same layer,and are integrally connected to each other by interconnection layerswhich traverse the drain distribution circuit DDC and which are formedin the same layer as and of the same material as the interconnectionlayers COM1 and COM2.

The lead line CL1 of the counter voltage signal line CL is electricallyconnected to the interconnection layer COM2 on the same side as theliquid crystal display part AR through a through-hole formed to extendthrough the protective film FPAS, the protective film PAS and theinterlayer insulating film IL1.

FIG. 42 is a plan view showing another embodiment of the liquid crystaldisplay device according to the invention, and is a view correspondingto FIG. 41B.

In the case of the construction shown in FIG. 41B, the number of theinterconnection layers which provide the connection between theinterconnection layer COM2 disposed along the drain distribution circuitDDC on the same side as the liquid crystal display part AR and theinterconnection layer COM1 disposed along the drain distribution circuitDDC on the opposite side to the liquid crystal display part AR is threeper predetermined length. As shown in FIG. 42, the number of suchinterconnection layers may be one per predetermined length.

In the case of this connection, it is possible to decrease the loadcapacitance of the drain distribution circuit DDC.

EMBODIMENT 13

FIGS. 43A, 43B and 43C are views showing the construction of anotherembodiment of the liquid crystal display device according to theinvention, and are views corresponding to FIGS. 41A, 41B and 41C,respectively.

As compared with Embodiment 11 shown in FIGS. 41A, 41B and 41C,Embodiment 13 has a different construction in that the interconnectionlayer COM disposed to surround the drain distribution circuit DDC isformed in the same layer as and of the same material as the drain signallines DL.

FIGS. 44 and 45 are plan views showing other embodiments of the liquidcrystal display device according to the invention, and are viewscorresponding to FIG. 43B.

In the case of the construction shown in FIG. 43B, the number of thelead lines CL1 of the counter voltage signal lines CL disposed tointersect the drain distribution circuit DDC is four for eachpredetermined length thereof, for example, in the case of theconstruction shown in FIG. 43B, but in the case of the constructionshown in FIG. 44, the number of such lead lines CL1 is, for example,two. In the case of the construction shown in FIG. 45, the countervoltage signal lines CL disposed to intersect the drain distributioncircuit DDC are formed to cover the whole of the area in which the draindistribution circuit DDC is formed. In the case of the constructionshown in FIG. 45, there is an advantage which decreases the electricalresistances of the counter voltage signal lines CL and theinterconnection layer COM itself.

EMBODIMENT 14

FIG. 46 is a view showing the construction of another embodiment of theliquid crystal display device according to the invention, and is a viewcorresponding to FIG. 37.

As compared with Embodiment 11 shown in FIG. 37, Embodiment 14 has adifferent construction in that the interconnection layer COM disposedclose to the drain distribution circuit DDC is formed on only theopposite side to the liquid crystal display part AR, but not on the sameside as the liquid crystal display part AR. In other words, theinterconnection layer COM has a construction in which only theinterconnection layer COM1 is formed.

Accordingly, the intersections of the drain signal lines DL with theother interconnection layer (the interconnection layer COM2) areomitted, thereby decreasing parasitic capacitance which occurs betweenthe drain signal lines DL and the other interconnection layer.

The reason why the interconnection layer COM1 is provided between thedrain distribution circuit DDC and the semiconductor chip TCP is asfollows. The frequency of a signal to be outputted from eachsemiconductor chip TCP to the drain distribution circuit DDC becomes ahigher frequency corresponding to the division number of the draindistribution circuit DDC.

In the case where such frequency is high, during signal generation inthe semiconductor chip TCP, when generated signals rapidly switch over,so-called gridges occurs, and the gridges need to be decreased by theinterconnection layer COM1. Accordingly, it is possible to avoid theproblem that unnecessary high voltage or noise is applied to the thinfilm transistors TFT in the liquid crystal display part AR and thereliability of the thin film transistors TFT lowers.

FIGS. 47A, 47B and 47B are views showing a further specific constructionof the embodiment shown in FIG. 46, and is a view corresponding to FIG.43.

The interconnection layer COM1 is formed on the upper surface of theinsulating film GI, and the lead line CL1 of the counter voltage signalline CL is formed on the upper surface of the protective film FPAS. Thelead line CL1 intersects the drain distribution circuit DDC, and isconnected to the interconnection layer COM1 through through-holes formedto extend through the protective film FPAS, the protective film PAS andthe interlayer insulating film IL1.

FIGS. 48 and 49 are plan views showing other embodiments of the liquidcrystal display device according to the invention, and are views eachcorresponding to FIG. 47B.

The number of counter voltage signal lines CL disposed to intersect thedrain distribution circuit DDC is four for each predetermined lengththereof, for example, in the case of the construction shown in FIG. 47Band two, for example, in the case of the construction shown in FIG. 48.In the case of the construction shown in FIG. 49, the counter voltagesignal lines CL disposed to intersect the drain distribution circuit DDCare formed to cover the whole of the area in which the draindistribution circuit DDC is formed. In the case of the constructionshown in FIG. 49, there is an advantage which decreases the electricalresistances of the counter voltage signal lines CL and theinterconnection layer COM itself.

In Embodiment 14, the interconnection layer COM1 is provided between thedrain distribution circuit DDC and the semiconductor chip TCP, and aninterconnection layer corresponding to the interconnection layer COM2 isnot provided. Accordingly, unnecessary high voltage is prevented frombeing applied to the drain distribution circuit DDC, and further,waveform rounding is prevented from occurring in a signal applied to thethin film transistors TFT in the liquid crystal display part AR, therebyproviding a construction which selectively satisfactorily achieves theadvantage of an improvement in reliability.

EMBODIMENT 15

FIGS. 50A, 50B and 50C are views showing the construction of anotherembodiment of the liquid crystal display device according to theinvention, and are views corresponding to FIGS. 47A, 47B and 47C,respectively.

As compared with Embodiment 15 shown in FIGS. 47A, 47B and 47C,Embodiment 15 has a different construction in that the interconnectionlayer COM1 is formed on the upper surface of the interlayer insulatingfilm IL1 in the same layer as the drain signal lines DL, and isconnected to the lead line CL1 of the counter voltage signal line CLformed on the upper surface of the protective film FPAS, throughthrough-holes formed to extend through the protective film FPAS, theprotective film PAS and the interlayer insulating film IL1.

FIGS. 51 and 52 are plan views showing other embodiments of the liquidcrystal display device according to the invention, and are views eachcorresponding to FIG. 50B.

In the case of the construction shown in FIG. 50B, the number of countervoltage signal lines CL disposed to intersect the drain distributioncircuit DDC is, for example, four for each predetermined length thereofin the case of the construction shown in FIG. 50B, but in the case ofthe construction shown in FIG. 51, the number of such counter voltagesignal lines CL is, for example, two. In the case of the constructionshown in FIG. 52, the counter voltage signal lines CL disposed tointersect the drain distribution circuit DDC are formed to cover thewhole of the area in which the drain distribution circuit DDC is formed.In the case of the construction shown in FIG. 52, there is an advantagewhich decreases the electrical resistances of the counter voltage signallines CL and the interconnection layer COM itself.

EMBODIMENT 16

FIG. 53 is a view showing another embodiment of the liquid crystaldisplay device according to the invention. Embodiment 16 shown in FIG.53 is intended for a construction in which in addition to the videosignal driver circuit provided on the side of one end of each drainsignal line DL, another video signal driver circuit is provided on theside of the other end of each drain signal line DL.

The video signal driver circuit is made of, for example, a constructionincluding the drain distribution circuit DDC connected to the drainsignal lines DL. In FIG. 53, the illustration of the portions(semiconductor chips) of the video signal driver circuit other than thedrain distribution circuit DDC is omitted.

The interconnection layer COM is formed to surround the draindistribution circuit DDC.

In this case as well, the line width of an interconnection layerdisposed along the drain distribution circuit DDC on the same side asthe liquid crystal display part AR is formed to be thinner than the linewidth of an interconnection layer disposed along the drain distributioncircuit DDC on the opposite side to the liquid crystal display part AR.

Incidentally, in the case where the video signal driver circuits areprovided on the opposite ends of each drain signal line DL, it is commonpractice to connect one of the video signal driver circuits to eacheven-numbered one of the drain signal lines DL and the other to eachodd-numbered one of the drain signal lines DL.

EMBODIMENT 17

FIG. 54 is a view showing the construction of another embodiment of theliquid crystal display device according to the invention. Embodiment 17shown in FIG. 54 has a construction in which an equalizing circuit EQCis formed at the other end of each drain signal line DL whose one end isconnected to a video signal driver circuit, and the interconnectionlayer COM is formed to surround the equalizing circuit EQC.

This equalizing circuit EQC is constructed to become a counter voltagesignal (COM) when a drain signal changes from high to low and when adrain signal changes from low to high, and becomes extremely effectivein the case of so-called dot-inversion driving or line-inversiondriving.

FIG. 62A is a circuit diagram of one embodiment of the equalizingcircuit EQC. Switching element Tr11, Tr12, Tr13, . . . are formed in therespective drain signal lines DL1, DL2, DL3, . . . , and the gates ofthe respective switching element Tr11, Tr12, Tr13, . . . are connectedto a line EQG. A line EQS1 is connected to the drain signal line DL1 viathe switching element Tr11, a line EQS2 is connected to the drain signalline DL2 via the switching element Tr12, and a line EQS3 is connected tothe drain signal line DL3 via the switching element Tr13.

In this case as well, the lead line CL1 of the counter voltage signalline CL disposed on the same side as the liquid crystal display part ARis extended to intersect the equalizing circuit EQC, and is connected tothe interconnection layer COM1.

FIG. 62B is a timing chart of the drain signal lines DL during normaldriving, and FIG. 62C is a timing chart of the drain signal lines DLduring equalizer driving. During equalizer driving, in one horizontalscanning period (1H), after the gate of the thin film transistors TFT ofthe pixel areas have been turned off, the signal voltages of the drainsignal lines DL are set to a common (reference) voltage (EQS1 or EQS2)via the respective switching element Tr11, Tr12, Tr13, . . . of theequalizing circuit EQC.

In the next horizontal scanning period (1H), voltages of oppositepolarity are written to the respective drain signal lines DL1, DL2, DL3,. . . .

Accordingly, it is possible to improve the efficiency of voltage writingto the drain signal lines DL and reduce power consumption owing to areduction in driver output load.

FIG. 55A is a circuit showing the equalizing circuit EQC, and FIG. 55Bshows an interconnection pattern of the equalizing circuit EQC formed onthe transparent substrate SUB1. FIG. 55B shows a pattern geometricallycorresponding to the pattern in FIG. 55A. FIG. 55C is a cross-sectionalview taken along line c—c of FIG. 55B.

The counter voltage signal line CL formed on the upper surface of theprotective film FPAS is extended to intersect the equalizing circuitEQC, and is electrically connected to the interconnection layer COM1formed along the equalizing circuit EQC on the opposite side to theliquid crystal display part AR.

FIGS. 56 and 57 are plan views showing other embodiments of the liquidcrystal display device according to the invention, and are views eachcorresponding to FIG. 55B.

The number of the lead lines CL1 of the counter voltage signal lines CLdisposed to intersect the equalizing circuit EQC is four for eachpredetermined length thereof, for example, in the case of theconstruction shown in FIG. 55B, but in the case of the constructionshown in FIG. 56, the number of such lead lines CL1 is, for example,two. In the case of the construction shown in FIG. 57, the countervoltage signal lines CL disposed to intersect the equalizing circuit EQCare formed to cover the whole of the area in which the equalizingcircuit EQC is formed. In the case of the construction shown in FIG. 57,there is an advantage which decreases the electrical resistances of thecounter voltage signal lines CL and the interconnection layer COMitself.

EMBODIMENT 18

FIG. 58 is a view showing the construction of another embodiment of theliquid crystal display device according to the invention, and is a viewcorresponding to FIG. 54.

As compared with Embodiment 17 shown in FIG. 54, Embodiment 18 has adifferent construction in that the interconnection layer COM disposedclose to the equalizing circuit EQC is formed on only the opposite sideto the liquid crystal display part AR, but not on the same side as theliquid crystal display part AR.

Accordingly, the intersections of the drain signal lines DL with theother interconnection layer (the interconnection layer COM2) areomitted, thereby decreasing parasitic capacitance which occurs betweenthe drain signal lines DL and the other interconnection layer.

FIGS. 59A, 59B and 59B are views showing a further specific constructionof the embodiment shown in FIG. 58, and are views each corresponding toFIGS. 55A, 55B and 55B.

EMBODIMENT 19

FIGS. 60 and 61 are plan views showing other embodiments of the liquidcrystal display device according to the invention, and are views eachcorresponding to FIG. 59B.

The number of counter voltage signal lines CL disposed to intersect thedrain distribution circuit DDC is four for each predetermined lengththereof, for example, in the case of the construction shown in FIG. 59Band two, for example, in the case of the construction shown in FIG. 60.In the case of the construction shown in FIG. 61, the counter voltagesignal lines CL disposed to intersect the drain distribution circuit DDCare formed to cover the whole of the area in which the draindistribution circuit DDC is formed. In the case of the constructionshown in FIG. 61, there is an advantage which decreases the electricalresistances of the counter voltage signal lines CL and theinterconnection layer COM itself.

EMBODIMENT 20

FIGS. 63 and 64 are schematic views showing different constructions ofEmbodiment 20 of the liquid crystal display device according to theinvention.

In the construction shown in FIG. 63, a annular-shaped interconnectionlayer COM is formed to extend along the periphery of the transparentsubstrate SUB1, and this interconnection layer COM is formed outside thescanning signal driver circuit GSCL and the video signal driver circuit.

In this case as well, the counter voltage signal line CL (or thecapacitance signal line CST1) is extended to intersect the scanningsignal driver circuit GSCL and the video signal driver circuit, and iselectrically connected to the interconnection layer COM.

As shown in FIG. 64, in a construction in which the video signal drivercircuit is provided with the drain distribution circuit DDC, theinterconnection layer COM may be formed to run through the portionbetween the drain distribution circuit DDC and the other circuit in thedrain current.

Moreover, it goes without saying that the above-describedinterconnection layer COM is partly formed so that the interconnectionlayer is formed to surround the scanning signal driver circuit GSCL, thevideo signal driver circuit, and the drain distribution circuit DDC orthe equalizing circuit EQC.

In any of the above-described embodiments, switching elements are madeof a semiconductor layer made of polysilicon. However, it goes withoutsaying that any of the embodiments can be applied to switching elementsmade of a semiconductor layer made of amorphous silicon or the like.

It also goes without saying that the above-described embodiments can beappropriately combined.

Moreover, each of the embodiments has been described with reference to aliquid crystal display device, but as long as the circuit constructionsand the pattern layouts of the circuit parts disclosed in the abovedescription of the embodiments are used, any of the embodiments canserve their advantages even in an image display device having no crystalliquid and using self-emission elements such as organicelectroluminescent elements or inorganic electroluminescent elements.

As is apparent from the foregoing description, in the liquid crystaldisplay device according to the invention, it is possible to restrainstatic electricity from entering the scanning signal driver circuit orthe video signal driver circuit. It is also possible to restrain theleak of light through the scanning signal driver circuit or the videosignal driver circuit. Furthermore, it is possible to prevent themalfunction of the scanning signal driver circuit or the video signaldriver circuit.

The invention is not limited to any of the above-describedconstructions, and can be modified in various ways without departingfrom the technical idea of the invention.

1. A display device comprising: a pair of substrates; a signal line, acapacitance line and a counter voltage line formed on one substrate ofthe pair of substrate; a pixel comprising a thin film transistorconnected to the signal line, a pixel electrode connected to the thinfilm transistor and a counter electrode connected to the counter voltageline; a driver circuit formed on the one substrate and connected to thesignal line; and a first interconnection layer disposed between thepixel and the driver circuit; wherein at least one of the capacitanceline and the counter voltage line is connected to the firstinterconnection layer between the driver circuit and the pixel; whereinthe signal line is a pate signal line; wherein the driver circuit is ascanning signal driver circuit; wherein the first interconnection layeris disposed between the scanning signal driver circuit and the pixel,and wherein a second interconnection layer is disposed between thescanning signal driver circuit and a nearest edge of the one substrateto the scanning signal driver circuit.
 2. A display device according toclaim 1, wherein: at least one of the capacitance line and the countervoltage line is connected to the second interconnection layer betweenthe scanning signal driver circuit and the nearest edge of the onesubstrate.
 3. A display device according to claim 1, wherein: a width ofthe first interconnection layer between the scanning signal drivercircuit and the pixel is smaller than a width of the secondinterconnection layer between the scanning signal driver circuit and thenearest edge of the one substrate.
 4. A display device comprising: apair of substrates; a signal line, a capacitance line and a countervoltage line formed on one substrate of the pair of substrate; a pixelcomprising a thin film transistor connected to the signal line, a pixelelectrode connected to the thin film transistor and a counter electrodeconnected to the counter voltage line; a driver circuit formed on theone substrate and connected to the signal line; and a firstinterconnection layer disposed between the pixel and a nearest edge ofthe one substrate to the driver circuit; wherein at least one of thecapacitance line and the counter voltage line is connected to the firstinterconnection layer at a position between the driver circuit and thenearest edge of the one substrate; wherein the signal line is a gatesignal line; wherein the driver circuit is a scanning signal drivercircuit; wherein the first interconnection layer is disposed between thescanning signal driver circuit and the nearest edge of the onesubstrate; wherein a second interconnection layer is disposed betweenthe scanning signal driver circuit and the pixel; and wherein a width ofthe second interconnection layer between the scanning signal drivercircuit and the pixel is smaller than a width of the firstinterconnection layer between the scanning signal driver circuit and thenearest edge of the one substrate.